Locomotive draft appliance



5 Sheets-Sheet 1 E. L. SCHELLENS ET AL LOCOMOTIVE DRAFT APPLIANCE FlledDec 18, 1925 April 8,

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April 8, 1930. E. L. SCHELLENS E AL LOCOMOTIYE DRAFT AIIPLIANCESSheets-Sheet Filed Dec. 18, 1923 N EN 0R3 4- ATTORNEYS April 8, 1930.

E. L. SCHELLENS ET AL LOCOMOTIVE DRAFT APPLIANCE 5 Sheets-Sheet 5 'FiledDec. 18, 1923 INVENTOR$ 4 ATTORNEYS rmwa'sa April 1930- E. L. SCHELLENSET AL I 1,753,906

'LOCOMOTIVE DRAFT APPLIANCE Filed Dc. 18, 1923 5 Shets-Sheet 4 I I 1VENTOILZ B W I mR/wsw April 8, 1930. E. L. SCHE'LLENS ET L LOCOMOTIVEDRAFT APPLIANCE 5 Sheets-Sheet 5 Filed Dec. 18, 1923 Bucky SPEED STEAMSPEED" VELOC/TY RAT/0.

INVENTORS g r 1 I I I BY M 1 W ATTORNEKS Patented Apr. 8, 1930 UNITEDSTATES PATENT OFFICE EUGENE L. SCHELLENS, OF POINTE CLAIRE, QUEBEC,CANADA, AND JOEL S. COFFIN, JR.., OF LISBON, NEW HAMPSHIRE, ASSIGNORS,BY MESNE ASSIGNMENTS, TO C-S ENGINEERING COMPANY, A CORPORATION OFDELAWARE LOOOMOTIVE DRAFT APPLIANCE Application filed December 18, 1923.Serial No. 681,450.

This invention relates to locomotive draft appliances and it has for oneof its primary objects the efficient drafting of the locomotive withminimum back pressure in the cylinders, whereby the efliciency of thelocomotive is increased.

Another object of our invention is the provision of an effective meansfor drafting a locomotive as a substitute for the customary exhauststeam blast used for the creation of the draft. In this connection ourinvention contemplates the creation of the draft by means of a fan, andwhile we are aware that heretofore it has been proposed to use a fan forthis purpose, yet in so far as we know no practical device of thischaracter has hitherto been employed.

Another object of our invention is to provide a draft device of the fantype the capacity of which can be readily altered to suit therequirements of any particular locomotive, so that one or two sizes willsufiice for practically all locomotives.

A further object of our invention is to provide an improved combineddraft appliance and feed water heater.

More specific objects and advantages 'will be hereinafter set forth inconnection with the description of the invention.

How the foregoing, together with such other objects and advantages asmay be incident toour invention, are obtained, is'illustrated in theaccompanying drawings show.- ing the preferred embodiments of ourinvention, and in which Fig. 1 is a vertical cross section through alocomotive front end or smoke box showing the application of ourimprovement;

Fig. 2 is a vertical section through the bearing means for the fanshaft, taken on the line 2'2 of Fig. 3 and illustrating the method ofprotecting the same and their lubrication;

Fig. 3 is a section taken on the line 3-3 of Fig. 2; p

Fig. 4 is a vertical section through the feed water heater proper; onthe line 4l4 of Fig. l

Fig. 5 is a section taken on the line 55 of Fig. 4:;

Fig. 6 is a top plan view of a detail of the heater;

Figs. 7, '8 and 9 are views illustrating details of the turbine nozzle,Fig. 8 being taken on the line 88 of Fig. 7

Fig. 10 is a partial plan and section of the fan;

Fig. 11 is a curve, illustrating certain principles involved in ourinvention, and Fig. 12 illustrates a detail of the device.

Referring now to Fig. 1, the reference character A indicates the frontend or smoke box of the locomotive, while the reference character Billustrates our combined stack, heater and draft appliance.

This draft appliance takes the place of the usual stack, although ofconsiderably larger size. In general it comprises the fan 7, the feedwater heater proper G, the economizer D, and the turbine drivingmechanism E.

The fan 7 is of the centrifugal type as we have found that, for thispurpose, the ordinary fan having the radial blades with straight pulland discharge, is not as effective. The fan comprises the hub 8; theupper disc or wall 9; the lower wall 10 spaced away from the wall 9 toprovide the lat.- erally directed discharge throat 11; and the blades orimpellers 12, secured to the walls 9 andolO, as illustrated in Fig. 10.All portions of the blades, with the exception of the attaching flanges,are vertical. The wall 10 is provided with an inner rim or neck portion13 upon which the buckets 14 of the turbine drive are mounted. A shroud15, if necessary, may be placed around the fan to assist in deflectingthe exhaust from the fan upwardly to clear the cab. The hub may beprovided with a plurality of tapped openings 16 for the insertion ofbalancing plugs, the matter of proper balance being an importantconsideration.

The fan 7 is mounted on the shaft 17. This shaft depends in theinnermost of three nested shells or housings 18, 19 and 20. The housing20 is welded or otherwise securely attached to the tube sheet 21 of theeconomizer D. The shell 19 is suspended within the housing 20 from thetop thereof, being welded or otherwise secured thereto. A dead air space22 is provided between these housings or shells to insulate the shaftand its bearings from the heat of the front end. The housing 18 isprovided 'ith laterally extending lugs 18 at the top and bolted to thehousing 20 by means of the bolts The housing 18 is provided withvertical ribs 24; cooperating with the shell 19 to provide verticalchannels communicating at the bottom with the space 25 between thehousing 18 and the shell 19. A disc 26 is secured over the top of thehousing 18 and is provided with three slots 27 in line with three of thechannels formed by the ribs 24:. The other three channels are blankedoff at the top by the disc, as will be clear from Fig. 3. The hub of thefan is provided with a plurality of apertures 28 above which the smallfan blades 29 are disposed so as to force air downwardly through suchapertures into the space 30 and down through the slots 2? in the disc26, the air thence flowing downwardly through three of the channelsabout the housing 18 and then upwardly through the other three channelsand thence outwardly between lugs 18, as indicated by the arrows inFigs. 2 and 3. This circulation of air is brought about by the fanblades 29 and the fact that three of the channels around the housing 18open laterally into the low pressure area of the fan T. Thus the fan inoperation sets up a cooling circulation of air around the housing 18.The shaft and its bearings are, therefore, further protected from theheat of the front end.

The shaft is provided with a radial bearing 31 at the top and with acombined radial and thrust bearing 32 at its lower end, both bearingsbeing carried within the housing 18. The housing 18 is filled with oilto about the level indicated in Fig. 2, the oil being introduced throughthe shaft 17 which is made hollow for this purpose. The oil iscirculated in the following manner.

As the shaft'revolves, the oil within the central opening therein wellsup in parabolical form and begins to flow out laterally through theinclined )ort 33 from which it is discharged by centri ugal force intothe vertical grooves 34 of the sleeve-like member 35 surrounding theshaft, and extending between the bearings. These grooves increase indepth upwardly so that centrifugal force continues to lift the oil,discharging it out through the one or more apertures 36 in the top ofthe sleeve 35 just beneath the bearing 31. The oil passes through suchbearing, lubricating the same and, if it overflows into the space 37above the hearing, it is returned to the bottom or sump portion of thehousing 18 by means of the port 38, lubricating the bearing 32 in itspassage downward. If the oil be kept at the proper level, the bearings32 will also be lubricated from beneath While at rest only.

It will thus be seen that the shaft and its bearings are protected bythe dead insulating space 22, by the flow of air through the channelsaround the housing 18 and by the circulation of the oil within thehousing 18, whereby overheating, which is one of the most seriousproblems in connection with apparatus of this character, is overcome.Immediately above the bearing 31 we provide a pad 39 which becomessoaked with oil insuring lubrication of the bearing 31 in starting thefan. This is advantageous in the event that the locomotive is idle forany length of time.

In order to maintain a predetermined level of oil within the housing 18,we provide a float 40 on the stem 4:1, the upper portion of which fitsinto the plug 12, acting as a valve to shut off further oil admissionwhen there is a proper level of oil within the housing. The plug 42 ishollow and receives a strainer 13, the opening being closed by the plug44. This arrangement is effective to prevent the ingress of any ui tinto the housing 18.

The bearing is positioned between the annular lip 4L5 and the sleeve 85,while the bearing 31 is positioned between the sleeve 35 and the collar16 which in turn is clamped by the hub of the fan and the nut 47. Inthis connection the length of the sleeve is such that when the nut 1? istightened, the sleeve 35 will be under some measure of compressionthereby securely supporting both bearings. The top of the housing 18 isclosed by a cap plate 48 and a packing t9 is provided between such plate#18 and the collar 16 to prevent dirt working its way within the housing18. Depending from the lower face of the hub is an annular ring or rib50 serving to enshroud the top of the housing 18.

By removal of the fan and the bolts 23, the fan shaft and bearings andthe housing 18 may be removed a unit.

Coming now to the economizer D, it will be seen that this comprises theupper tube sheet 21 hereinbefore referred to; the shell 51; the bottomtube sheet 52 and the nest of tubes 53, the lower ends of which openinto the smoke box and the upper ends into the low pressure area of thefan. The tubes are arranged in annular rows, the diameter of the tubesof the various rows being successively smaller. By this arrangement itis possible to greatly increase the number of tubes, as the result ofwhich a maximum area of heat transferring surface is obtained.

The smoke box gases are drawn through the tubes 53 and dischargelaterally outward and upward from the fan, and, in passing through thetubes, they give off appreciable heat to the feed water in theeconomizer, such feed water passing from the heater C thru the outlets54 into the economizer drum. It will be observed on inspection of F 1that the outlets 5a discharge about midway of the height of theeconomizer, as a result of which there is a downward and then an upwardcirculation of the water in the economizer. The feed water is taken fromthe upper portion of the economizer drum by means of the pipes in orderto prevent the formation of any air pockets in the drum. The pipes 55 ofwhich there may be any desired number lead to a header 56 from whichpipes lead outwardly through the smoke box shell to the injectors (notshown). For cleaning out purposes, pipes 57 lead from the bottom of theeconomizer drum to the exterior where they are provided with blow oii'cocks 58. The economizer drum is suspended in the front end by means ofthe steam chest or manifold 59 resting upon and secured to the front endshell, as will further appear.

The heater C will now be described. This heater includes the shell 60which is welded to the bottom portion of the housing 20 and to which, inturn, the bottom tube sheet 52 of the economizer drum is welded. Thelower end of the casing 60 has a flange 61 which serves as a means forpositioning the heater casing 62 through the medium of the ring 63 andthe studs 64 as will be clear from inspection of Fig. l. The casing 62carries at its top a tube sheet 65 and at the bottom there is anothertube sheet .66 which, however, is flexibly carried in the manner to bedescribed. The lower end of the casing 62 is open and is adapted to beclosed by the cap or end plate 67 and the flexible diaphragm 68, suchdiaphragm being clamped between the tube sheet 66 and the plate 67 andbetween the bottom of the casing 62 and the ring 69. The plate 67 andthe tube sheet 66 thus cooperate to form a header which is flexiblymounted with respect to the casing 62 to take care of expan sion andcontraction of the nests of tubes 70, the ends of which are expanded orwelded in the tube sheets 65 and 66.

Feed water is introduced into the header formed by the plates 67 and thetube sheet 66 through a suitable pipe 71 secured to the in let 72. Theinterior of the header is divided into two compartments 73 and 74 by thedivision wall 75, the upper end of which takes against the tube sheet66. The entering feed water passes through compartment 73 and upwardlythrough the nest of tubes opening from such space into the compartment76 formed by the plate 77. From this compartment 76, feed water flowsdown the next pass or nest of the tubes leading downwardly from suchcompartment to the compartment 74. From compartment 74 the feed waterpasses through the third or last pass upwardly into the space 78, fromwhich space most of the feed water discharges through the openings 54before described, although a portion may also flow downwardly andoutwardly through the discharge ports 54*.

The feed water is heated by exhaust steam introduced into the casing 62,the steam being supplied by means of the elbow 79, the lower end ofwhich is fastened to the usual nozzle stand base 80 of the saddlecasting,

whereby exhaust steam from the cylinders enters the casing. Exhauststeam from the auxiliary engines may be led to the casing by means ofthe pipes 81. The entering steam flows upwardly toward the upper part ofthe casing and then downwardly over the baffle 82, this baffle beingprovided for the purpose of securing a circulation of steam and theelimination of any dead spaces. The outlet of the casing 62 is indicatedat 83 in Fig. 1, from inspection of which it will be noted that suchoutlet is of comparatively restricted character. By virtue of thisrestricted outlet only so much steam as can be properly condensed in thefeed water heater flows into the heater casing. The use of more steamthan is required for this purpose is unnecessary, would introducecomplications in the dispo- '.tion of the surplus steam, and woulddiminish unnecessarily the volume available for driving the draft fanhereinafter to be described.

V'Vith reference to the tubes 70, as before described, they are arrangedin three parallel passes, one succeeding another transversely of theheater. Ordinarily the tube nests are disposed according to a radial orsegmental arrangement of passes, the first and last of which are besideone another and have a maximum temperature difference, representing thedifference between the initial temperature and the final temperature. Asa result, two adjacent nests of tubes have to accommodate an expansioncaused by a maximum temperature difference. By our arrangement ofparallel succeeding sections or passes, the water flows progressivelyfrom one to the next with the result that the total temperaturedifference is divided by three. Thus a minimum difference in expansionexists between two adjacent sections. With this minimum difference inexpansion, the stresses are kept well within the elastic limit of thetubes. However, by virtue of the diaphragm 68, the lower tube sheet hasa capacity to tilt and weave a slight amount thereby reducing thestresses in the tubes to a very appreciable extent.

The housing 20 and the shell 60 cooperate to constitute a centralstrength member for the economizer drum.

Referring now to the turbine and partieularly Figs. 1, 7, 8, 9 and 12,it will be seen that the steam chest or manifold 59 is open at the topand has secured over such open top, a nozzle ring 84, provided with aplurality of nozzles 85. The nozzle has a bowl portion 86, a throat 87and a mouth 88. The nozzle passages have their upper and lower surfacesdefined by the steel plates 89, provided to extend the life of theturbine. A number of tapped holes are provided in the nozzle ring forthe purpose of securing a blanking strip or strips over certain of thenozzle mouths, an arran ement affording a means for altering thecapacity of the turbine and fan to suit the requirements of theparticular engine, thus making one size capable of wide application. Thebuckets 1 1 are of usual construction.

Exhaust steam is led to the turbine chest from each steam chest of thelocomotive by a pipe 91. The cross sectional area of the pipes 91 issuch as to conduct the exhaust steam freely to the manifold 59, and thetotal area of the nozzles, due to their number, resulting from the largediameter of the turbine, is such that the maximum back pressure in themain engine cylinders will be very low as compared to standard practice,say, for xample, in the neighborhood of 2 to 3 pounds.

The turbine is intentionally designed to 0perate at such low pressure,preferably at 2. 1 pounds per square inch. -With this low pressure weare enabled to obtain maximum nozzle and bucket efficiency as will beclear from the following. For the particular class of service, the fanshould not operate at too great speed and we have so designed theapparatus that the peripheral speed of the buckets mounted adjacent thefan periphery at rated load, should be approximately 350 ft. per second. The nozzle and bucket efficiency will increase with increase of thevelocity ratio, i. e., bucket speed over steam speed. With a pressure inthe fan steam chest or manifold of 2.1 pounds per square inch exhaustingto the atmosphere, the velocity of the steam will be approximately 744ft. per second. If now the curve of 11 be examined, it will be seen thatthe velocity ratio (bucket speed divided by steam speed) equals .47, atwhich the nozzle and bucket efficiency is a little below 80 per cent. Byway of comparison if we assume a pressure of 200 pounds per square inchin the manifold exhausting to atmosphere, the velocity of the steamwould be 3120 ft. per second giving a velocity ratio of .112 and anozzle and bucket efiiciency in the neighborhood of 30 per cent.

It will be seen, therefore, that with the permissible fan speed it isessential, in order to have a practical device, to operate the turbinewith very low pressure, and to design the fan to provide adequate draftat the speeds at wh ch maximum efficiency of the nozzle and buckets canbe obtained. The combination of the large-diameter, low pressureoperated turbine and the large-diameter, axial-intake andcentrifugal-discharge fan obtains the desired results. In thisconnection it should again be noted that both fan and turbine aremounted on top of the smoke-box at the stack outlet, and are thereforeunrestricted by the inherent space limitations of the same. In

other words, by mounting the fan and its driving means as shown, theirdiameter may be increased beyond what has heretofore been possible inthe art, with the result that unrestricted intake and discharge areasare possible for the fan, and lower steam pressures may be used on theturbine, which gives greater nozzle and bucket efficiencies ashereinbefore set forth, and as shown in Fig. 11.

In order to operate the fan at times when no exhaust steam is availablefor such purpose and also in order to obtain a maximum degree offlexibility, we provide means for supplying boiler pressure steam to theturbine. For this purpose we provide one high pressure nozzle 96 in thenozzle ring ea, having a bowl portion 96, communicating with a. specialcavity 92 in the manifold 52), to which cavity high pressure steam isconducted by means of the pipe 93. This is illustrated in Fig. 12. Thissingle high pressure nozzle will develop approximately one-quarter ofthe power of the low pressure nozzles and thus the fan may be operatedwhen the locomotive is standing or is about to be started. Similarly attimes of high overload, the high pressure nozzle may be used tosupplement the low pressure nozzle affording the requisite flexibilityof the draft appliance. Under ordinary conditions a draft blast will beproduced proportionate to the amount of steam being used, automaticallycreating a draft appropriate for the particular operating conditions.The draft will be continuous, of large volume, and of low velocity, sothat there will be no tendency to pull holes in the fire bed or exhaustsparks or cinders. In fact the usual front end netting, which is asource of great trouble and expense, may be dispensed with.

If needed as a provision against racing of the fan, an ordinary safetyor relief valve may be attached to the steam chest at the point marked94 in Fig. 12. For the purpose of supporting the economizer drum againstrotation we provide one or more studs 95 as shown in Fig. 1.

e claim:

1. In a locomotive draft appliance, a stack and an exhaust-stcam-drivencentrifugally discharging fan for producing draft, said fan beinglocated at the stack outlet.

2. In combination with a locomotive and its smoke-box and stack, aturbine operated by the locomotive exhaust, and a draft fan driven bysaid turbine, approximating the smokebox in diameter, and positionedastride said smoke box, axially of the stack, so as to be unrestrictedin its effective intake and discharge area by the normal spacelimitations of said smoke box.

In combination with a locomotive and its smoke-box, anexhaust-steam-driven fan draft appliance, with at least the fan, proper,

thereof positioned without the confines of the smoke-box andapproximating it in diameter, said draft appliance including alowpressure exhaust-steam operated turbine positioned peripherally ofthe fan.

4. In a locomotive draft appliance, a stack, a centrifugal draft fantherefor mounted on a substantially vertical axis, and means around theperiphery thereof for deflecting the discharge therefrom upwardly aroundit.

5. In a locomotive draft appliance, a stack, a centrifugal draft fanmounted on a vertical axis at the top thereof, and ashroud disposedperipherally of the fan and spaced away therefrom.

6. In a draft appliance having a fan runner and bearing means thereforwith airchannel means associated therewith, auxiliary fan blades on saidrunner positioned to circulate a draft of cooling air through saidchannel means to the intake side of the fan.

7. In a locomotivedraft appliance, a stack,

a draft fan revolving about a substantially vertical axis, a shafttherefor having bearings, a housing for said bearings mounted in saidstack, and a second housing exterior of the first housing providing aninsulating space therebetween.

8. In a locomotive draft appliance, a stack, a draft fan revolving abouta substantially vertical axis, a shaft therefor having bearings, ahousing for said bearings mounted in said stack, and a second housingexterior of the first housing providing an insulating spacetherebetween, together with means additionally subjecting said firsthousing to a cooling medium. 7

9. In a locomotive draft appliance, a stack, a draft fan revolving abouta substantially vertical axis, a shaft therefor having bearings, a fixedhousing for said bearings mounted in the stack, and means forcirculating a cooling medium in contact with said housing.

10. In a locomotive draft appliance, a stack, a draft fan revolvingabout a substantially vertical axis, a shaft therefor having bearings, afixed housing for said bearings mounted in the'stack, and means forcirculating a cooling medium exterior of the housmg.

11. In a locomotive draft appliance, a stack, a draft fan revolvingabout a substantially vertical axis, a shaft therefor having bearings, ahousing for said bearings, and means for circulating a cooling mediumwithin and also exterior of the housing.

12. In a locomotive draft appliance, a stack, a draft fan revolvingabout a substantially vertical axis, a shaft therefor having bearings, ahousing for said bearings, an oil bath in the housing, and meansexternally cooling the housing. Y

13. In a locomotive draft appliance, a stack, a draft fan revolvingabout a substantially vertical axis, a shaft therefor having bearings,and three nested housings for said bearings providing an insulatingspace and a space through which a cooling medium may be applied.

14:. In a locomotive draft appliance, a stack, a draft fan revolvingabout a substantially vertical axis, a shaft therefor having bearings, ahousing for said bearings, and

troduced into the housing from the top of said shaft.

17 In a locomotive draft appliance, a draft fan revolving about asubstantially vertical axis, a shaft therefore having bearing means, ahousing for the shaft and bearing means the lower portion of whichserves as an oil sump, and means associatedwith the shaft whereby theshaft when revolving lifts the oil, said means serving also to space thebearlngs.

18. In a locomotive draft appliance, a draft fan revolving about asubstantially vertical axis, a shaft therefor having bearing means, ahousing for the shaft and bearing means the lower portion of whichserves as an oil sump, a conduit extending into the sump, and meansassociated with the shaft whereby the shaft when revolving lifts oilthrough. said conduit.

19. In a locomotive draft appliance, a stack, a fan therefor and itsshaft, a housing for the shaft, and means for supplying oil to thehousing through the shaft controlled by the oil level.

20. In a locomotive draft appliance, a stack, a fan therefor and itsshaft, a housing for the shaft, means for introducing oil to thehousing. and an oil level indicating and shut-off float operatingthrough said shaft,

21. A fan for drafting a locomotive comprising a fan runner rotatablymounted on said locomotive, said fan runner comprising a hub memberextended into a dished web, vanes rigidly mounted on said web a dishedcover rigidly fixed to said vanes, said web and said cover guiding theflow of exhaust gases from the furnace of said locomotive thru said fanrunner in such a manner as to insure that the direction of flow of saidgases at any mounted steam nozzles arranged to direct steam against saidbuckets and steam conducting means whereby steam is conducted to saidnozzles.

In testimony whereof, We have hereunto signed our names.

E. L. SGHELLENS. J. S. COFFIN,JR.

